Process for treating a substrate in order to improve the behaviour thereof with regard to malodorous molecules

ABSTRACT

The present invention provides a method of treating a substrate in order to improve its properties of absorbing malodorous molecules, in particular associated with sweat, the method comprising the following steps:
         i) preparing an acid aqueous composition comprising at least one organosilane A having at least one hydrolyzable alcoxy group, and at least one main polycarboxylic acid B comprising at least four —COOH carboxyl groups or its corresponding anhydride comprising at least four —COO—CO groups; the weight ratio of said at least one organosilane A over the weight of said at least one main polycarboxylic acid B, lying in the range 0.8 to 1.2;   ii) applying said composition on said substrate; and   iii) heating said substrate comprising said composition to a temperature higher than or equal to 120° C., preferably higher than or equal to 130° C., in order to polymerize said organosilane A with at least the main polycarboxylic acid B or its corresponding anhydride.

BACKGROUND OF THE INVENTION

The present invention relates to the technical field of methods of treating substrates in order to improve their behavior relative to bad odors, in particular in order to confer properties of absorbing malodorous molecules on said substrates, such as textile elements, and/or in order to improve such properties.

Substrates, such as textile materials or foams, do not all react in the same manner with respect to bad odors, and in particular odors produced by the body of a wearer of said substrates, such as odors stemming from sweat being degraded by bacteria present on the surface of the skin.

Natural materials, such as cotton, smell less sweaty than synthetic materials, such as polyester. Wearers of synthetic materials generally complain that the bad odors supported by a textile, in particular when practicing a sport or immediately afterwards, appear much more quickly when they are wearing a garment made of synthetic material than when they are wearing a garment made of natural material, or even of regenerated or artificial material, such as viscose, for example.

The bad odors supported by a substrate, such as a textile, come from the degradation of the sweat that is absorbed by bacteria present on the surface of the skin.

One technical solution for combating bad odors consists in treating the substrate so as to impart antibacterial properties thereto in order to destroy the bacteria involved in the sweat degradation process. Such treatments are generally performed on the basis of a composition comprising trichlosan, chitosan, copper, silver, or indeed quaternary ammonium.

US 2009/0206296 A1 relates to applying to a textile a composition comprising an organosilane in order to reduce the tendency of said textile to emit bad odors by preventing, or at least decreasing, the adhesion of molecules on the textile, and thus the adhesion of bacteria. That composition further comprises an alcohol as a solvent and an acid catalyst. In particular, that document seeks to decrease the number of hydrogen functions at the surface of textiles, since according to the inventors they are responsible for bonds that the textile element forms with external molecules such as spots of dirt or bacteria that might generate bad odors. Textiles treated in that way prevent the adhesion and deposition of molecules by decreasing or even eliminating any potential hydrogen bonds at the surface of the textile.

WO 2007/099144 relates to a method of treating a textile in order to impart antimicrobial properties thereto. The composition always comprises at least one cationic surfactant, such as a quaternary ammonium salt, and a glycol ether. The composition may also comprise epoxy or amino alcoxy silanes mentioned among numerous ingredients in a first exhaustive list and a polycarboxylic acid mentioned in a second exhaustive list, but none of those compounds is used in combination in the examples. The preferred acids are hydrochloric acid or acetic acid. The quaternary ammonium salts used are well known for imparting bactericidal properties to a textile.

It has also been observed that destroying bacteria present in the substrate does not combat bad odors as effectively as when the treatment is in contact with the skin.

The above-mentioned documents thus seek to develop a bactericidal treatment in order to limit the generation of bad odors by diminishing the number of bacteria present on the skin.

This thus implies that the bactericidal treatment comes into contact directly with the skin in order to act on the target bacteria. Those treatments are thus effective on bacteria when they are applied to substrates that are to be worn next to the body, but they are ineffective for substrates that are not designed to be worn next to the body.

Those treatments also have the drawback that they may be allergenic, in particular when they come into contact with the skin, possibly in combination with the substrate rubbing against the skin.

Finally, the above-mentioned solutions do not seek to act on the malodorous molecules, which may be volatile, but only on the bacteria, in order to avoid said malodorous molecules being produced by preventing the bacteria from adhering to the substrate or by destroying them.

Once the malodorous molecules have been produced, antibacterial treatment has no effect on them.

FR 2 984 343 B1 describes a sol-gel method of fabricating a functional coating on a textile medium. The composition used comprises a first sol-gel precursor in combination with a second sol-gel precursor carrying a functional group and/or in combination with functional particles. In the example mentioned, the weight ratio of silanes over succinic acid is of the order of 3.29, the weight of carboxylic acid being much less than the weight of organosilanes. The looked-for properties for the coating are water repellency, crease recovery, or indeed resistance to abrasion. Managing odors does not form part of the looked-for properties for the textile medium.

The publication entitled “Durable hydrophobic cellulose fabric prepared with polycarboxylic acid catalyzed silica sol”, Ind. Eng. Chem. Res. 2010, 49, 9135-9142, describes a sol-gel for forming a hydrophobic coating on a cotton substrate. The composition thus comprises tetraethoxylorthosilcate (TEOS) in combination with sodium hypophosphite and a polycarboxylic acid. The proportion by weight of polycarboxylic acid is much greater than that of silane since the ratio between the silane (TEOS) (Si%=1 w/w) and the carboxylic acid constituted by butane tetracarboxylic acid (BTCA) present at 1.03 M is of the order of 0.042.

The hydrophobic properties given to a substrate limit the adhesion of bacteria to some extent, in particular when they are conveyed by water, e.g. sweat, and thus limit proliferation of bacteria on the textile itself. However, that property has no effect on generating odors, e.g. when they stem from sweat and are produced on the skin. Modifying the water absorption properties of a substance, and thus its sweat absorption properties, can also give rise to a substrate that is uncomfortable, in particular for practicing a sport, since it does not absorb sweat and thus leaves sweat in contact with the skin, a medium that is favorable to the proliferation of bacteria and thus to generating odors.

There thus exists a need for a substrate that manages bad odors and that presents water absorption properties that are not significantly modified as a result of the treatment it has received for managing odors.

OBJECT AND SUMMARY OF THE INVENTION

The present invention seeks to propose a substrate, in particular a synthetic substrate, in particular based on polyester, that is suitable for absorbing malodorous molecules in significant manner, in particular molecules given off by the body, in particular produced when sweat is degraded by bacteria, and for this to apply regardless of whether the substrate is worn next to the body.

The present invention also seeks to propose a substrate, in particular a synthetic substrate, that absorbs bad odors throughout its lifetime, i.e. even after it has been washed many times.

The present invention also seeks to provide an improved method of treating a substrate that is simple to implement and inexpensive.

In a first aspect, the present invention thus provides a method of treating a substrate in order to improve its properties of absorbing malodorous molecules, in particular molecules associated with sweat, the method comprising the following steps:

i) preparing an aqueous composition comprising at least one organosilane A having at least two hydrolyzable alcoxy groups, and at least one main polycarboxylic acid B comprising at least four —COOH carboxyl groups, or its corresponding anhydride; the weight ratio of said at least one organosilane A over the weight of said at least one main polycarboxylic acid B, or its corresponding anhydride, lying in the range 0.8 to 1.2;

ii) applying said composition on said substrate; and

iii) heating said substrate comprising said composition to a temperature higher than or equal to 120° C., preferably higher than or equal to 130° C., in order to polymerize said organosilane A with at least the main polycarboxylic acid B or its corresponding anhydride.

The inventors have discovered that applying a composition as defined above leads to synergy of means for conferring gas-absorption properties to said substrate, e.g. a textile element, in particular for absorbing gases that are considered to be malodorous, which properties are significant, i.e. olfactively perceptible by the wearer of said substrate, e.g. a textile element. In particular, at the end of the heating step iii), the substrate is coated, in full or in part, by a polymer coating that results from the polymerization reaction between the organosilane A and the polycarboxylic acid B or its corresponding anhydride.

Advantageously, it has been observed that the aqueous composition of the invention makes it possible to confer odor-absorption properties on the substrate without modifying its water-handling properties. The method of the invention thus advantageously does not form a hydrophobic coating on the treated surface of the substrate. The similar, or indeed equivalent, weight proportions between said at least one organosilane A and said at least one main acid B or its corresponding anhydride thus makes it possible to functionalize the substrate relative to odors without modifying its water absorption properties.

The above-mentioned weight of said at least one organosilane A corresponds to the weight of one or more organosilane(s) A of the invention.

The above-mentioned weight of said at least one main polycarboxylic acid B, or its corresponding anhydride, corresponds to the weight of one or more main polycarboxylic acid(s) B, or of the corresponding anhydride(s), of the invention.

Preferably, the weight ratio of said at least one main polycarboxylic acid B, or its corresponding anhydride, over the weight of compounds present in the aqueous composition, with the exception of water, is greater than or equal to 20%, more preferably greater than or equal to 30%, still more particularly greater than or equal to 40%.

Preferably, the weight ratio of said at least one main organosilane A over the weight of compounds present in the aqueous composition, with the exception of water, is greater than or equal to 20%, more preferably greater than or equal to 30%, still more particularly greater than or equal to 40%.

In the meaning of the present text, the term “substrate” is used to designate any medium suitable for absorbing bad odors, and in particular that is to absorb bad odors coming directly or indirectly from sweat. Preferably, said substrate may be a layer made of one or more cellular materials, e.g. one or more layers of foam, or a textile element, or mixtures thereof.

In the meaning of the present text, the term “textile element” designates a multifilament yarn, a fiber spun yarn, a monofilament yarn, a textile article such as a knit, a woven fabric, or a nonwoven fabric, or mixtures thereof.

Said substrate may form all or part of a sole, a handbag, a blanket for an animal, a clothing article, such as a short or long sleeved T-shirt, shorts, trousers, a jacket, a cap, a hat, a sock, an undergarment, or a bath or beach towel.

For example, said textile article may comprise all or part of a sweat-protection cushion or pad placed in the rear portion of a backpack for the purpose of coming into contact with the user's back when the backpack is being worn.

Preferably, said substrate, in particular said cellular material(s) or said textile element, in particular the fiber spun yarn, the multifilament yarn, the monofilament yarn, and the fibers making up the nonwoven fabric, is/are made of one or more synthetic materials, i.e. materials obtained from chemical compounds derived from hydrocarbons or from starch, and in particular from hydrocarbons.

Preferably, said substrate, and in particular said cellular material(s) or said textile element, in particular the fiber spun yarn, the multifilament yarn, the monofilament yarn, and the fibers making up the nonwoven fabric, is/are selected independently from the list comprising synthetic, artificial, and natural materials and mixtures thereof, and in particular from the list comprising: polyethylene terephthalate, polypropylene, polyethylene, polyamide 6-6, polyamide 6, polyamide 12, polyamide 4-6, polyacrylonitrile, polyacrylic, spandex, polyurethane, polytrimethyleneterephthalate (PTT), polybutylene terephthalate (PBT), and mixtures thereof, as synthetic materials forming a sub-list I; wool, silk, cotton, and mixtures thereof, as natural materials forming a sub-list II; viscose, modal, lyocell, cupro (artificial silk), and tencel, and mixtures thereof, as artificial materials forming a sub-list III; more preferably from the sub-list I and/or the sub-list III; still more particularly from the sub-list I. Preferably, said textile element is dyed before being subjected to the method of the invention.

The composition of the invention can thus be applied to the textile element in the yarn state or in the textile article state, e.g. as a fabric or a knit.

The substrate of the invention may be subjected to treatment to give it a capacity to absorb water or an aqueous medium (e.g. sweat), referred to in the state of the art as hydrophilic treatment. This type of hydrophilic treatment is well known to the person skilled in the art (e.g. by applying a hydrophilic polymer by a wet technique or by applying plasma treatment). Advantageously, it has been observed that the method of the invention does not modify the properties of a hydrophilically treated substrate for absorbing water or an aqueous medium.

In the meaning of the present text, the term “absorber/absorption” is used to designate any phenomenon that enables a target molecule that is considered as being malodorous to be retained inside the coating (absorption) and/or at the surface of said coating (adsorption). The exact nature of the interactions between the target molecules and the polymer coating that is formed is not known. It may thus involve any chemical or physical bond. Without seeking to be limited by any particular theory, it would appear that van der Waals interactions and/or hydrogen interactions and/or electrostatic interactions are taking place; in particular they may be van der Waals interactions.

The malodorous target molecules are preferably selected from the list comprising: propanoic acid, benzothiazole, acetic acid, methyl disulfide, valeric acid, trimethylamine, pyrazine, dodecanoic acid, octanoic acid, toluene, 1,3-octenol, ethanol, diacetyl, isopropyl alcohol, 2-methyl hexadodecanol, 1-eicosene, 2-phenoxyethanol, ethyl acetamide, nonanoic acid, aniline, benzene, 1-hexadecanol, decane, ethylene glycol, ethyl methacrylate, octane, ammonia, 2-nonenal, and dimethyl succinate, more preferably it comprises acetic acid and ammonia.

Preferably, the pH of the aqueous composition is acidic, i.e. less than or equal to 6, more preferably less than or equal to 4, still more particularly less than or equal to 3, in particular greater than or equal to 1.

Preferably, the heating temperature in step iii) is higher than or equal to 140° C., more preferably higher than or equal to 150° C., and in particular higher than or equal to 160° C.

Preferably, the heating temperature in step iii) is lower than or equal to 210° C., more preferably lower than or equal to 200° C., particularly lower than or equal to 190° C., still more particularly lower than or equal to 180° C.

Preferably, the heating time in step iii) is greater than or equal to 15 seconds, more preferably greater than or equal to 30 seconds, in particular greater than or equal to 1 minute, more particularly greater than or equal to 5 minutes.

Preferably, the heating time in step iii) is less than or equal to 60 minutes, preferably less than or equal to 15 minutes, more particularly less than or equal to 10 minutes.

Preferably, the stirring time in step i) is greater than or equal to 5 minutes, more preferably greater than or equal to 10 minutes, particularly greater than or equal to 15 minutes, more particularly greater than or equal to 30 minutes, and in particular less than or equal to 120 minutes.

Preferably, the composition is not heated in step i). Advantageously, step i) is performed at ambient temperature, in particular at a temperature higher than or equal to 15° C., and lower than or equal to 35° C.

Naturally, depending on the country in which the aqueous composition is prepared, ambient temperature may be of the order of 35° C.-40° C.

Preferably, the aqueous composition is applied to said substrate, e.g. to said textile element, by padding or by impregnation, followed by squeezing to remove the excess aqueous composition taken up by the textile element. Preferably, said substrate is subjected to a first pass during which the aqueous composition is applied thereto, and then said substrate including said aqueous composition is squeezed, and more preferably the substrate is subjected to a second pass, preferably similar to the first pass.

The number of passes depends on the concentration of organosilane A and of acid B in the composition. It is thus possible for a single pass to suffice.

In an implementation, the squeezing pressure applied to said substrate, e.g. to the textile element, lies in the range 0.5 bars to 6 bars, and preferably in the range 1 bar to 6 bars, and in particular in the range 2 bars to 5 bars. In particular, during the first pass, the substrate, e.g. the textile element, travels at a speed faster than or equal to 0.5 meters per minute (m/min), more preferably faster than or equal to 1 m/min. By way of example, the travel speed of the substrate is faster than or equal to 10 m/min, preferably lying in the range 15 m/min to 20 m/min.

In an implementation, the substrate is subjected to at least one wash after heating step iii), preferably using tap water or demineralised water, possibly having a washing additive added thereto, for at least 5 minutes, preferably for at least 15 minutes. In particular, the washing may be performed in cold water or in water at a temperature higher than or equal to 30° C., in particular lower than or equal to 90° C., more particularly lower than or equal to 60° C. The wash(es) is/are preferably performed in a washing machine. The washing may thus be performed by the user.

It is necessary to wash the substrate at least once in order for it to present its significant bad odor absorbing properties of the invention. This washing may be performed personally by the user of the substrate.

The anhydride corresponding to the polycarboxylic acid B comprises at least four —COO—CO groups.

The aqueous composition may optionally comprise at least one other carboxylic acid, i.e. having at least one —COOH carboxyl group, or its corresponding anhydride, i.e. comprising at least one —COO—CO function, in particular selected from the following list: formic acid, citric acid, succinic acid, acetic acid, their corresponding anhydrides, and mixtures thereof.

The present invention may also have added thereto an acid, other than a carboxylic acid or its corresponding anhydride, e.g. hydrochloric acid or sulfuric acid, in order to adjust the acid pH of the aqueous composition.

Preferably, as carboxylic acids or their corresponding anhydrides, the aqueous composition comprises only polycarboxylic acids having at least four —COOH carboxyl groups, and/or their corresponding anhydrides having at least four —COO—CO groups, in particular having at most ten —COOH and/or —COO—CO groups, more particularly having at most six —COOH and/or —COO—CO groups.

The organosilane A comprises at least one hydrolyzable group, which is thus hydrolysed since the organosilane A is in an aqueous medium.

In the meaning of the present text, the term “hydrolyzable group” is used to mean any group suitable for being separated from the silicon atom under the effect of the decomposition of water generating H₃O⁺ and OH⁻ ions, in particular under the effect of H₃O⁺ ions in the context of the present invention, since the pH of the aqueous binding composition is less than or equal to 6.

The hybridized organosilane A in the aqueous composition forms an equivalent silanol and an alcohol during the first hydrolysis reaction.

Preferably, the organosilane is selected from an organodialcoxysilane or an organotrialcoxysilane, more preferably from an epoxy dialcoxysilane or an epoxytrialcoxysilane or a vinyldialcoxysilane or a vinyltrialcalcoxyoxysilane or an aminodialcoxysilane or an aminotrialcoxysilane, more preferably from an epoxy dialcoxysilane or an epoxytrialcoxysilane.

In a variant, the organosilane A has the following formula (I) [R₄—(SiR₁R₂R₃)]_(n) where n is an integer such that 1≦n≦100, R₄ is a non-hydrolyzable group and at least one group from among R₁, R₂, and R₃ is a hydrolyzable group; preferably, 1≦n≦75, more preferably 2≦n≦50, 2≦n≦40, in particular 2≦n≦25, specifically 2≦n≦15. Under such circumstances, the organosilane is an oligomer. When n is equal to 1, the organosilane is a monomer. Preferably, n is equal to 1.

In a variant, R₄, and optionally R₁ and/or R₂ and/or R₃ when representing one or more non-hydrolyzable groups, represent(s) independently of one another a group selected from: a C1-C20 alkyl group or a C3-C10 cycloalkyl group substituted by one or more epoxy groups, said epoxy group being mono, di, tri, or tetravalent; a glycidoxy group; a C1-C20 alkyl group substituted by a glycidoxy group; a (CH₂═CH—) vinyl group; a C1-C20 alkyl group substituted by a (CH₂═CH—) vinyl group; a C1-C20 vinyl group substituted by a primary amine and/or a secondary amine and/or a tertiary amine; a primary amine; a secondary amine; a tertiary amine; an isocyanate group; a C1-C20 alkyl group substituted by an isocyanate group.

Also, at least one group from R₁, R₂, and R₃ represents as a hydrolyzable group, a hydroxyl group (—OH), a C1-C10 alkoxy group, a C3-C10 cycloalkoxy group, a C5-C10 aryloxy group or a C1-C5 acyloxy group, preferably a C1-C10 acyloxy group and/or a hydroxyl group (—OH), more preferably a C1-C10 alkoxy group.

Said above-mentioned alkyl groups, whether concerning the hydrolyzable group or the non-hydrolyzable group, are saturated, linear or branched, being C1-C20, preferably C1-C15, and more preferably C1-C10, and the cycloalkyl groups are saturated, and preferably C3-C6.

In the meaning of the present invention, when a group is Cn-Cp (also written Cn to Cp), that means that it presents n to p carbon atoms, where n and p are integers.

By way of example, the monovalent epoxy groups are the glycidoxy group, —O—CH₂—C₂H₃O or indeed the R_(i)—C₂H₃O (or Ri-oxirane) group in which R_(i) is an alkyl chain that may be linear or branched, saturated or non-saturated, a cycloalkyl, an alkenyl, an aryl, an ether, or a polyether. The above-mentioned alkyl chains are preferably C1 to C10, and the above-mentioned cycloalkyls are preferably C3 to C10, and more preferably C3 to C6.

By way of example, the divalent epoxy groups are the following groups -(-)C(—O—)CR_(ii)R_(iii) and —CR_(ii)(—O—)CR_(iii)—, by way of example the trivalent epoxy groups are the following groups -(-)C(—O—)CR_(ii), by way of example of the tetravalent epoxy groups are the following groups -(-)C(—O—)C(-), in which R_(ii) and R_(iii) are independently one or another of the structures selected from those listed above for R_(i).

In the meaning of the present invention, the term “alkoxy group” is used to mean any group of formula Ra—O in which Ra represents an alkyl group that is saturated and linear or branched, optionally including an —OH function, preferably being C1 to C10, more preferably being C1 to C6, still more preferably being C1 to C4, such as for example the following groups: methoxy, ethoxy, isopropoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, and n-hexyloxy.

In the meaning of the present invention, the term “cycloalkyloxy group” means any group of formula Rb—O in which Rb represents a cycloalkyl group, preferably being C3 to C10, such as the cyclopropyloxy and cyclohexyloxy groups.

In the meaning of the present invention, the term “cycloalkyl group” means any cyclic alkyl group, preferably being C3 to C10, e.g. the cyclohexyl or cyclopropyl group.

In the meaning of the present invention, the term “aryloxy group” means any group of formula Rc-O in which Rc represents an alkyl group, preferably being C5 to C10, such as for example the phenoxy group.

In the meaning of the present invention, the term “aryl group” means one or more aromatic cycles advantageously having 5 to 10 carbon atoms, which may be adjacent or fused. In particular, the aryl groups may be monocyclic or bicyclic groups, preferably being the phenyl group.

In the meaning of the present invention, the term “alkoxy group” means any group of formula Rd-CO—O in which Rd represents an alkyl group that is saturated and linear or branched, preferably being C1 to C4, such as for example the acetoxy and propionyloxy groups.

Among the alkoxy groups, the methoxy, ethoxy, and isopropoxy groups in particular are the preferred hydrolyzable groups, more preferably the methoxy or ethoxy group, particularly the methoxy group.

In the meaning of the present invention, the term “primary amine” is used to mean any group of formula R_(e)NH₂, the term “secondary amine” is used to mean any group of formula R_(e)R_(f)NH, and the term “tertiary amine” is used to mean any group of formula R_(e)R_(f)R_(g)N, in which R_(e), R_(f) and R_(g) are alkyl groups that are saturated or non-saturated, linear or branched, and preferably C1 to C20, or more preferably C1 to C10, and still more preferably C1 to C4.

In the meaning of the present invention, the term “isocyanate group” means any group of formula R_(m)—N═C═O in which R_(m) is a hydrogen atom or an alkyl chain that is saturated or not saturated, linear or branched, preferably C1 to C20, more preferably C1 to C10, and still more preferably C1 to C4.

In the meaning of the present invention, the term “alkenyl group” means any group of formula R_(o)R_(p)C═CR_(r)R_(s) in which R_(o), R_(p), R_(r), and R_(s) are independently of one another a hydrogen atom or an alkyl chain that may be saturated or not saturated, linear or branched, preferably C1 to C20, more preferably C1 to C10, and still more preferably C1 to C4, such as, for example, a vinyl group.

In a variant, R₁ and/or R₂ and/or R₃, preferably R₁ and R₂, R₂ and R₃, or R₁ and R₃, more preferably R₁, R₂, and R₃, represent an alkoxy group, a cycloalkoxy group, an aryloxy group, or an acyloxy group, a hydroxyl group (—OH), preferably an alkoxy group.

In a variant, R₁ and R₂, R₂ and R₃, or R₁ and R₃ are alkoxy groups, and R₁ or R₂ or R₃ is a hydroxyl group (—OH).

In a variant, R₄ is an alkyl group substituted by an epoxy group, preferably a glycidoxy group, of formula X—Y— attached to the silicon atom, in which X is a glycidoxy group, —O—CH₂—C₂H₃O; or an oxirane; and Y is a group selected from: —(CH₂)n—, with 1≦n≦12, more preferably with 1≦n≦6.

In a variant, the alkoxy group is selected from the following groups: methoxy, ethoxy, propoxy, isopropoxy, isobutoxy, acetoxy, methoxyethoxy, monovalent alkoxy groups derived from diols comprising an alcohol and an alkoxy selected from —O—CH₂CH₂—OH, such as ethylene glycol; propylene glycol; neopentyl glycol; 1,3-propanediol; 2-methyl-1,3-propanediol; 1,3-butanediol; 2-methyl-2,4-pentanediol; 1,4-butanediol; cyclohexane dimethanol; picanol, preferably from among the methoxy; ethoxy; propoxy; and isopropoxy groups.

In a variant, the oligomer of organosilane A is selected from a list comprising: gamma-glycidoxypropyltrimethoxysilane; gamma-glycidoxypropyltriethoxysilane; gamma-glycidoxypropyl methyldimethoxysilane; gamma-glycidoxypropylmethyldiethoxysilane; vinyltriethoxysilane, vinyltriethoxysilane, dimethyldimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isobutyltriethoxysilane, methyltrimethoxysilane, preferably from the list comprising: gamma-glycidoxypropyltrimethoxysilane; gamma-glycidoxypropyltriethoxysilane; gamma-glycidoxypropylmethyldimethoxysilane; gamma-glycidoxypropylmethyldiethoxysilane, more preferably gamma-glycidoxypropyltrimethoxysilane.

In a variant, the organosilane A comprises at least three alkoxy groups.

In a variant, the organosilane is an epoxy organosilane.

In a variant, the main polycarboxylic acid B is 1,2,3,4 butane tetracarboxylic acid, or its corresponding anhydride.

In a variant, the aqueous composition comprises, relative to the total weight of its dry weight, at least 20% by weight, preferably at least 30% by weight, more preferably at least 40% by weight, still more preferably at least 45% by weight of said at least one organosilane A. In the meaning of the present text, the term “dry mass” of the aqueous composition is used to mean the residual dry weight once the volatile compound(s) has/have evaporated, in particular compounds having a boiling point lower than or equal to 100° C. at atmospheric pressure. In particular it is constituted by water. Preferably, the residual dry weight corresponds to the weight (g) of the aqueous composition from which the weight of water that it contains (g) has been subtracted.

Said at least one organosilane A of the invention, although generally being liquid at ambient temperature and atmospheric pressure, is considered in the invention as being a dry compound, since it is not a compound that is aqueous or volatile, i.e. a compound that evaporates at a temperature lower than or equal to 100° C. at atmospheric pressure.

The weight of said at least one organosilane A corresponds to the weight of one or more organosilane(s) A of the invention.

In a variant, the aqueous composition comprises, relative to the total weight of its dry weight, at least 20%, preferably at least 30% by weight, more preferably at least 40% by weight, more particularly at least 45% by weight of said at least one main carboxylic acid B or its corresponding anhydride.

The weight of said at least one main carboxylic acid B, or its corresponding anhydride, corresponds to the weight of one or more main carboxylic acid(s) B, or of the corresponding anhydride(s), of the invention.

In a variant, the ratio in said composition of the weight of said at least one organosilane A over the weight of said at least one main carboxylic acid B, or its corresponding anhydride, lies in the range 0.9 to 1.1. The above-mentioned bounds are included within the range.

In a variant, at the end of the heating step iii), the weight gain (g) by said substrate due to dry matter of said aqueous composition is greater than or equal to 1%, preferably greater than or equal to 3%, also preferably less than or equal to 20%, particularly less than or equal to 15%, more particularly less than or equal to 10%.

The weight gain is calculated relative to the weight of the substrate, e.g. the textile element, after step iii), possibly after at least one wash followed by drying, and the weight of the textile element before step i).

In a variant, said substrate is a textile element comprising yarns of polyethylene terephthalate, polypropylene, polyethylene, polyamide 6-6, polyamide 6, polyamide 12, polyamide 4-6, polyacrylonitrile, polyacrylic, spandex, polyurethane, polytrimethyleneterephthalate (PTT), butylene polyterephthalate (PBT), and mixtures thereof, in particular polyethylene terephthalate.

In a second aspect, the present invention provides the use of an aqueous composition of the first aspect of the invention and comprising at least one organosilane A having at least one hydrolyzable group and at least one main polycarboxylic acid B having at least four —COOH acid carboxyl groups, or its corresponding anhydride, for giving odor-absorbing properties to a substrate.

Advantageously, the ratio of the weight of said at least one organosilane A over the weight of said at least one main carboxylic acid B, or its corresponding anhydride, in said composition lies in the range 0.8 to 1.2.

In a variant, said substrate is made of one or more synthetic materials and the organosilane A is selected from epoxy trialkoxysilanes.

The various implementations and definitions given above in a first aspect apply equally independently of one another to the invention in a second aspect.

In a third aspect, the present invention provides a substrate, e.g. a textile element, obtained by performing the above-described method in any of the variant implementations given with reference to the first aspect, presenting an odor reduction ratio measured in application of the ISO 17299-3:2014 standard of March 2014 and entitled “Textiles—determination of deodorant properties—Part 3: gas chromatography method” that is greater than or equal to 65%.

In a variant, said substrate is a textile element comprising by weight relative to its total weight at least 15% of fiber spun yarns and/or multifilament yarns and/or fibers or a layer of foam, made of one or more synthetic materials, in particular materials selected from the list comprising: polyethylene terephthalate; polypropylene; polyethylene; polyamide 6-6; polyamide 6; polyamide 12; polyamide 4-6; poly acrylonitrile; polyacrylic; spandex; polyurethane; polytrimethyleneterephthalate (PTT); polybutylene terephthalate (PBT); and mixtures thereof.

In a variant, said substrate is a textile element comprising by weight relative to its total weight at least 15% of fiber spun yarns and/or multifilament yarns and/or fibers or a layer of foam made of one or more artificial materials, in particular materials selected from the list comprising viscose, modal, lyocell, cupro, tencel, and mixtures thereof.

The technical characteristics given with reference to a first, second, or third aspect, may be combined independently of one another.

DETAILED DESCRIPTION OF EXAMPLES

The present invention can be better understood on reading the examples described below and mentioned in non-limiting manner.

The results of tests 1 to 12 and the aqueous compositions are given in Table 1. The proportions of acid(s) B and of organosilane A are expressed in grams per liter (g/L).

The last three columns give the odor reduction rates obtained respectively after one, ten, and twenty washes. These rates are measured using the ISO 172299-3:2014 standard of March 2014 and entitled “Textiles—determination of deodorant properties—Part 3: gas chromatography method”. Calculating the reduction rate is specified in point 8 of this standard and corresponds to the difference in the mean area of the hydrogen flame ionization detector (FID) spectrum of the test gas without the textile element (Sb) minus the mean area of the FID peak of the test gas with the textile element (Sm), this difference being taken relative to the area Sb and then multiplied by 100. Thus, values that are negative or zero indicate that there was no reduction in the target gas. The target gas used in the measurements listed below was acetic acid.

It should be observed that the above-referenced ISO 17299-3:2014 standard dating from March 2014 makes provision for one wash prior to performing measurements of target gas absorption.

Tests 1 to 11 were performed on undyed washed polyethylene terephthalate (PET) fabrics; only test 10 was performed on a dyed PET fabric.

For tests 1 to 8, the fabrics were subjected to the following methods: the organosilane A, in particular gamma-glycidoxypropyltrimethoxysilane (GPTMS) was mixed with the acid B and then the volume of the mixture was adjusted so as to obtain 1 liter of water, preferably demineralized water, at ambient temperature, in particular at 30° C., e.g. for 60 minutes in step i). Then in a step ii), a sample of PET fabric was subjected to a first pass during which the sample of fabric was padded and then squeezed (pressure of 4 bars at a travel speed of 1 meter per minute). Step ii) further comprised a second pass identical to the first pass. The sample of fabric impregnated with the aqueous composition was then subjected to a drying step for 3 minutes at 110° C. followed by a heating step iii) during which the sample of fabric was subjected to a temperature of 170° C. for 5 minutes. Depending on the concentration of organosilane A and of acid B, and on the viscosity of the aqueous composition (which can be adjusted by thickening agents, e.g. based on carboxymethylcellulose), a single pass might suffice.

Test 9 differs from tests 1 to 8 in that it had only one pass in step ii), and did not include the drying step.

Test 10 differs from tests 1 to 8 in that it included a single pass in step ii), it did not include a drying step, and in that in step iii), the temperature was 190° C. for 5 minutes.

Test 11 differs from tests 1 to 9 in that it had only one pass in step ii), it did not have a drying step, and in that, in step iii), the temperature was 190° C. for 9 minutes.

For tests 1 to 11, the pH of the aqueous composition was greater than or equal to 1.5 and less than or equal to 2.5.

The samples of treated fabric were subjected to at least one wash.

Preferably, washing was performed in conventional manner in a washing machine for at least 15 minutes, optionally using a washing powder/liquid.

On reading Table 1, it can be seen that when the aqueous composition had only the organosilane A, the reduction rate was very low after one wash, and down to zero after more than ten washes.

When the aqueous composition comprised only formic acid, oxalic acid, or succinic acid, the reduction rates were zero or extremely low. When citric acid, which is a triacid, was added to the aqueous composition, the reduction rate exceeded 50% after one and ten washes, but was zero after twenty washes. The coating that is formed is thus not long-lasting on a textile element that, in use, in particular for regularly practicing sports, will be washed many times. Furthermore, the inventors have observed by olfactory tests performed with a panel of 12 “experts” that they perceive an odor reduction for a reduction rate of at least 65%; the reduction is clearly perceived by users for a reduction above 80%, and better still for a reduction above 90%. It has been observed in particular that test 9 enables odors to be reduced as effectively as for a textile element made of cotton, with a reduction of odors that is much better than that had been observed for a fabric made of non-treated polyester.

TABLE 1 Measured Measured Measured odor odor odor Formic reduction reduction reduction acid Citric Oxalic Succinic ratio (%) ratio (%) ratio (%) GPTMS BTCA (85%) acid acid acid after 1 after 10 after 20 Test (g/L) (g/L) (g/L) (g/L) (g/L) (g/L) wash washes washes 1 40 40 — — — — 85.07 68.3 66.75 2 20 — — — — — 19.24 −3 — 3 40 — 40 — — — −3 28 −2 4 40 — 20 — — — 0 31 40 5 40 — 60 — — — 2 3 −2 6 40 — 20 31 — — 58 58 2 7 40 — 20 — — 40 37 54 20 8 40 — 20 — 15 — 11 23 27 9 40 40 — — — — 93 90 72 10 60 60 — — — — 68 94 94 11 40 40 — — — — 58 87 84

Table 2 below gives the reduction rates obtained for an aqueous composition comprising 3-aminopropyltriethoxysilane (APTS) as organosilane A. In Table 2, the reduction rate was measured in the same manner as for Table 1. In performing the method of the invention, test 12 differs from tests 1 to 8 only in that it had only one pass in step ii), that the organosilane A was APTS, and that it did not include a drying step.

The reduction rate obtained was good after a first wash, however it can be seen that this reduction rate collapsed after ten washes.

TABLE 2 Measured Measured Measured odor odor odor reduction reduction reduction ratio (%) ratio (%) ratio (%) APTS BTCA after after after Test (g/L) (g/L) 1 wash 10 washes 20 washes 12 40 40 97 38 28

In conclusion, it can thus be seen from the results of Tables 1 and 2 that the combination of organosilane A with a polycarboxylic acid having at least four —COOH carboxyl groups makes it possible to achieve reduction rates greater than 80%, or indeed greater than 90%, even after ten or twenty washes. The coating of the invention formed on the textile element serves to reduce odors very significantly and in a manner that is clearly perceptible for the user, said coating remaining effective even after many washes, in particular when it is an epoxyorganosilane.

Measuring the Dynamic Liquid Transport Properties of a Polyester (PET) Fabric Given Hydrophilic Treatment and then Treated by the Method of the Invention

This method consisted in placing a sample of polyester fabric between two moisture sensors and depositing a drop of a liquid on one of the faces of the fabric and then measuring the speed with which the drop passes through the fabric. The drop of liquid had conductivity of the order of 16 millisiemens (mS) (distilled water mixed with sodium chloride). The test was performed at ambient temperature, in particular at 20° C.±2° C., and with relative humidity of 65%±4% at atmospheric pressure.

The tested polyester fabrics were subjected to treatment to make them hydrophilic, which treatment is conventional and known to the person skilled in the art.

A controlled polyester fabric that was not treated by the method of the invention, presenting a weight per square meter of 130 g/m², and a thickness of 0.57 mm±1.75%, was subjected to at least one wash and presented a speed of passage for the drop of water from one face of the fabric to the other of 5.2 millimeters per second (mm/s)±22%.

A polyester fabric treated using the method of the invention (the composition of test 10) having a weight per square meter of 130 g/m², and a thickness of 0.57 mm±1.75%, and that had been subjected to at least one wash, presented a speed of travel for the drop of water from one face of the fabric to the other of 6.8 mm/s±22%.

Advantageously, the method of the invention conferring odor-absorbing properties on a substrate does not modify its initial water absorption properties.

The treatment of the invention thus cannot be considered as being equivalent to a hydrophobic treatment, since it has no repulsive effect relative to water. 

1. A method of treating a substrate in order to improve its properties of absorbing malodorous molecules wherein said method comprises the following steps: i) preparing an acid aqueous composition comprising at least one organosilane A having at least two hydrolyzable alcoxy groups, and at least one main polycarboxylic acid B comprising at least four —COOH carboxyl groups or its corresponding anhydride comprising at least four —COO—CO groups; the weight ratio of said at least one organosilane A over the weight of said at least one main polycarboxylic acid B, or its corresponding anhydride, lying in the range 0.8 to 1.2; ii) applying said composition on said substrate; and iii) heating said substrate comprising said composition to a temperature higher than or equal to 120° C., in order to polymerize said organosilane A with at least the main polycarboxylic acid B or its corresponding anhydride.
 2. The method according to claim 1, wherein the organosilane A comprises at least three alcoxy groups.
 3. The method according to claim 1, wherein the organosilane is an epoxyorganosilane.
 4. The method according to claim 3, wherein the epoxyorganosilane A is selected from the list comprising: gamma-glycidoxypropyltrimethoxysilane; gamma-glycidoxypropyltriethoxysilane; gamma-glycidoxypropylmethyldimethoxysilane; and gamma-glycidoxypropylmethyldiethoxysilane.
 5. The method according to claim 1, wherein the main polycarboxylic acid B is 1, 2, 3, 4 butanetetracarboxylic acid or its corresponding anhydride.
 6. The method according to claim 1, wherein the aqueous composition comprises, relative to the total weight (g) of its dry weight (g), at least 20% by weight (g) of said at least one organosilane A.
 7. The method according to claim 1, wherein the aqueous composition comprises, relative to the total weight (g) of its dry weight, at least 20% by weight, of said at least one main carboxylic acid B or its corresponding anhydride.
 8. The method according to claim 1, wherein the weight gain (g) by said substrate in dry matter of said aqueous composition at the end of the heating step iii) is greater than or equal to 1%.
 9. The method according to claim 1, wherein the substrate is made of one or more synthetic materials.
 10. The method according to claim 1, wherein the substrate is made of one or more artificial materials.
 11. The method according to claim 9, wherein the substrate is a textile element comprising yarns and/or fibers made of said synthetic and/or artificial materials.
 12. A method of using an aqueous composition comprising at least one organosilane A having at least one hydrolyzable group and at least one main polycarboxylic acid B comprising at least four —COO carboxyl groups, or its corresponding anhydride, for giving odor-absorbing properties to a substrate, the weight ratio of said at least one organosilane A over the weight of said at least one main polycarboxylic acid B, or of its corresponding anhydride, lying in the range 0.8 to 1.2.
 13. The method according to claim 12, wherein said substrate is made of one or more synthetic and/or artificial materials, and in that the organosilane A is selected from epoxy trialcoxysilanes and epoxy dialcoxysilanes.
 14. A substrate obtainable by performing a method according to claim 1, wherein said substrate presents an odor reduction ratio measured in application of the ISO 17299-3:2014 standard of March 2014 and entitled “Textiles—determination of deodorant properties—Part 3: gas chromatography method” that is greater than or equal to 65%.
 15. The substrate according to claim 14, wherein said substrate is a textile element comprising by weight relative to its total weight at least 15% of fiber spun yarns and/or multifilament yarns and/or fibers or a layer of foam, made of one or more synthetic materials.
 16. The substrate according to claim 14, wherein said substrate is a textile element comprising by weight relative to its total weight at least 15% of fiber spun yarns and/or multifilament yarns and/or fibers or a layer of foam made of one or more artificial materials.
 17. The method according to claim 1, wherein the aqueous composition comprises, relative to the total weight (g) of its dry weight (g), at least 30% by weight (g) of said at least one organosilane A.
 18. The method according to claim 1, wherein the aqueous composition comprises, relative to the total weight (g) of its dry weight, at least 30% by weight, of said at least one main carboxylic acid B or its corresponding anhydride.
 19. The method according to claim 1, wherein the weight gain (g) by the substrate in dry matter of said aqueous composition at the end of the heating step iii) is greater than or equal to 3%.
 20. The method according to claim 10, wherein the substrate is a textile element comprising yarns and/or fibers made of said synthetic materials selected from the list comprising: polyethylene terephthalate; polypropylene; polyethylene; polyamide 6-6; polyamide 6; polyamide 12; polyamide 4-6; poly acrylonitrile; polyacrylic; spandex; polyurethane; polytrimethyleneterephthalate (PTT); polybutylene terephthalate (PBT); or mixtures thereof. 